1. 
 Ade, P. A. R., et al.
(författare)

XXIV. Cosmology from SunyaevZeldovich cluster counts
 2016

Ingår i: Astronomy and Astrophysics.  : EDP Sciences.  00046361 . 14320746. ; 594

Tidskriftsartikel (refereegranskat)abstract
 We present cluster counts and corresponding cosmological constraints from the Planck full mission data set. Our catalogue consists of 439 clusters detected via their SunyaevZeldovich (SZ) signal down to a signaltonoise ratio of 6, and is more than a factor of 2 larger than the 2013 Planck cluster cosmology sample. The counts are consistent with those from 2013 and yield compatible constraints under the same modelling assumptions. Taking advantage of the larger catalogue, we extend our analysis to the twodimensional distribution in redshift and signaltonoise. We use mass estimates from two recent studies of gravitational lensing of background galaxies by Planck clusters to provide priors on the hydrostatic bias parameter, (1  b). In addition, we use lensing of cosmic microwave background (CMB) temperature fluctuations by Planck clusters as an independent constraint on this parameter. These various calibrations imply constraints on the presentday amplitude of matter fluctuations in varying degrees of tension with those from the Planck analysis of primary fluctuations in the CMB; for the lowest estimated values of (1 b) the tension is mild, only a little over one standard deviation, while it remains substantial (3.7 sigma) for the largest estimated value. We also examine constraints on extensions to the base flat Lambda CDM model by combining the cluster and CMB constraints. The combination appears to favour nonminimal neutrino masses, but this possibility does little to relieve the overall tension because it simultaneously lowers the implied value of the Hubble parameter, thereby exacerbating the discrepancy with most current astrophysical estimates. Improving the precision of cluster mass calibrations from the current 10%level to 1% would significantly strengthen these combined analyses and provide a stringent test of the base Lambda CDM model.


2. 
 Ade, P. A. R., et al.
(författare)

Planck 2015 results XIV. Dark energy and modified gravity
 2016

Ingår i: Astronomy and Astrophysics.  : EDP Sciences.  00046361 . 14320746. ; 594

Tidskriftsartikel (refereegranskat)abstract
 We study the implications of Planck data for models of dark energy (DE) and modified gravity (MG) beyond the standard cosmological constant scenario. We start with cases where the DE only directly affects the background evolution, considering Taylor expansions of the equation of state w(a), as well as principal component analysis and parameterizations related to the potential of a minimally coupled DE scalar field. When estimating the density of DE at early times, we significantly improve present constraints and find that it has to be below similar to 2% (at 95% confidence) of the critical density, even when forced to play a role for z < 50 only. We then move to general parameterizations of the DE or MG perturbations that encompass both effective field theories and the phenomenology of gravitational potentials in MG models. Lastly, we test a range of specific models, such as kessence, f(R) theories, and coupled DE. In addition to the latest Planck data, for our main analyses, we use background constraints from baryonic acoustic oscillations, typeIa supernovae, and local measurements of the Hubble constant. We further show the impact of measurements of the cosmological perturbations, such as redshiftspace distortions and weak gravitational lensing. These additional probes are important tools for testing MG models and for breaking degeneracies that are still present in the combination of Planck and background data sets. All results that include only background parameterizations (expansion of the equation of state, early DE, general potentials in minimallycoupled scalar fields or principal component analysis) are in agreement with ACDM. When testing models that also change perturbations (even when the background is fixed to ACDM), some tensions appear in a few scenarios: the maximum one found is similar to 2 sigma for Planck TT + lowP when parameterizing observables related to the gravitational potentials with a chosen time dependence; the tension increases to, at most, 3 sigma when external data sets are included. It however disappears when including CMB lensing.


3. 
 Abdalla, E., et al.
(författare)

Cosmology intertwined : A review of the particle physics, astrophysics, and cosmology associated with the cosmological tensions and anomalies
 2022

Ingår i: Journal of High Energy Astrophysics.  : Elsevier BV.  22144048 . 22144056. ; 34, s. 49211

Tidskriftsartikel (refereegranskat)abstract
 The standard Λ Cold Dark Matter (ΛCDM) cosmological model provides a good description of a wide range of astrophysical and cosmological data. However, there are a few big open questions that make the standard model look like an approximation to a more realistic scenario yet to be found. In this paper, we list a few important goals that need to be addressed in the next decade, taking into account the current discordances between the different cosmological probes, such as the disagreement in the value of the Hubble constant H0, the σ8–S8 tension, and other less statistically significant anomalies. While these discordances can still be in part the result of systematic errors, their persistence after several years of accurate analysis strongly hints at cracks in the standard cosmological scenario and the necessity for new physics or generalisations beyond the standard model. In this paper, we focus on the 5.0σ tension between the Planck CMB estimate of the Hubble constant H0 and the SH0ES collaboration measurements. After showing the H0 evaluations made from different teams using different methods and geometric calibrations, we list a few interesting new physics models that could alleviate this tension and discuss how the next decade's experiments will be crucial. Moreover, we focus on the tension of the Planck CMB data with weak lensing measurements and redshift surveys, about the value of the matter energy density Ωm, and the amplitude or rate of the growth of structure (σ8,fσ8). We list a few interesting models proposed for alleviating this tension, and we discuss the importance of trying to fit a full array of data with a single model and not just one parameter at a time. Additionally, we present a wide range of other less discussed anomalies at a statistical significance level lower than the H0–S8 tensions which may also constitute hints towards new physics, and we discuss possible generic theoretical approaches that can collectively explain the nonstandard nature of these signals. Finally, we give an overview of upgraded experiments and nextgeneration space missions and facilities on Earth that will be of crucial importance to address all these open questions.


4. 
 Aghanim, N., et al.
(författare)

Planck 2018 results I. Overview and the cosmological legacy of Planck
 2020

Ingår i: Astronomy and Astrophysics.  : EDP Sciences.  00046361 . 14320746. ; 641

Tidskriftsartikel (refereegranskat)abstract
 The European Space Agency's Planck satellite, which was dedicated to studying the early Universe and its subsequent evolution, was launched on 14 May 2009. It scanned the microwave and submillimetre sky continuously between 12 August 2009 and 23 October 2013, producing deep, highresolution, allsky maps in nine frequency bands from 30 to 857 GHz. This paper presents the cosmological legacy of Planck, which currently provides our strongest constraints on the parameters of the standard cosmological model and some of the tightest limits available on deviations from that model. The 6parameter Lambda CDM model continues to provide an excellent fit to the cosmic microwave background data at high and low redshift, describing the cosmological information in over a billion map pixels with just six parameters. With 18 peaks in the temperature and polarization angular power spectra constrained well, Planck measures five of the six parameters to better than 1% (simultaneously), with the bestdetermined parameter (theta (*)) now known to 0.03%. We describe the multicomponent sky as seen by Planck, the success of the Lambda CDM model, and the connection to lowerredshift probes of structure formation. We also give a comprehensive summary of the major changes introduced in this 2018 release. The Planck data, alone and in combination with other probes, provide stringent constraints on our models of the early Universe and the largescale structure within which all astrophysical objects form and evolve. We discuss some lessons learned from the Planck mission, and highlight areas ripe for further experimental advances.


5. 
 Aghanim, N., et al.
(författare)

Planck 2018 results VI. Cosmological parameters
 2020

Ingår i: Astronomy and Astrophysics.  : EDP Sciences.  00046361 . 14320746. ; 641

Tidskriftsartikel (refereegranskat)abstract
 We present cosmological parameter results from the final fullmission Planck measurements of the cosmic microwave background (CMB) anisotropies, combining information from the temperature and polarization maps and the lensing reconstruction. Compared to the 2015 results, improved measurements of largescale polarization allow the reionization optical depth to be measured with higher precision, leading to significant gains in the precision of other correlated parameters. Improved modelling of the smallscale polarization leads to more robust constraints on many parameters, with residual modelling uncertainties estimated to affect them only at the 0.5 sigma level. We find good consistency with the standard spatiallyflat 6parameter Lambda CDM cosmology having a powerlaw spectrum of adiabatic scalar perturbations (denoted base Lambda CDM in this paper), from polarization, temperature, and lensing, separately and in combination. A combined analysis gives dark matter density Omega (c)h(2)=0.120 +/ 0.001, baryon density Omega (b)h(2)=0.0224 +/ 0.0001, scalar spectral index n(s)=0.965 +/ 0.004, and optical depth tau =0.054 +/ 0.007 (in this abstract we quote 68% confidence regions on measured parameters and 95% on upper limits). The angular acoustic scale is measured to 0.03% precision, with 100 theta (*)=1.0411 +/ 0.0003. These results are only weakly dependent on the cosmological model and remain stable, with somewhat increased errors, in many commonly considered extensions. Assuming the baseLambda CDM cosmology, the inferred (modeldependent) lateUniverse parameters are: Hubble constant H0=(67.4 +/ 0.5) km s(1) Mpc(1); matter density parameter Omega (m)=0.315 +/ 0.007; and matter fluctuation amplitude sigma (8)=0.811 +/ 0.006. We find no compelling evidence for extensions to the baseLambda CDM model. Combining with baryon acoustic oscillation (BAO) measurements (and considering singleparameter extensions) we constrain the effective extra relativistic degrees of freedom to be Neff=2.99 +/ 0.17, in agreement with the Standard Model prediction Neff=3.046, and find that the neutrino mass is tightly constrained to Sigma m(nu)< 0.12 eV. The CMB spectra continue to prefer higher lensing amplitudes than predicted in base CDM at over 2 sigma, which pulls some parameters that affect the lensing amplitude away from the Lambda CDM model; however, this is not supported by the lensing reconstruction or (in models that also change the background geometry) BAO data. The joint constraint with BAO measurements on spatial curvature is consistent with a flat universe, Omega (K)=0.001 +/ 0.002. Also combining with Type Ia supernovae (SNe), the darkenergy equation of state parameter is measured to be w(0)=1.03 +/ 0.03, consistent with a cosmological constant. We find no evidence for deviations from a purely powerlaw primordial spectrum, and combining with data from BAO, BICEP2, and Keck Array data, we place a limit on the tensortoscalar ratio r(0.002)< 0.06. Standard bigbang nucleosynthesis predictions for the helium and deuterium abundances for the baseCDM cosmology are in excellent agreement with observations. The Planck baseLambda CDM results are in good agreement with BAO, SNe, and some galaxy lensing observations, but in slight tension with the Dark Energy Survey's combinedprobe results including galaxy clustering (which prefers lower fluctuation amplitudes or matter density parameters), and in significant, 3.6 sigma, tension with local measurements of the Hubble constant (which prefer a higher value). Simple model extensions that can partially resolve these tensions are not favoured by the Planck data.


6. 
 Aghanim, N., et al.
(författare)

Planck intermediate results XLVI. Reduction of largescale systematic effects in HFI polarization maps and estimation of the reionization optical depth
 2016

Ingår i: Astronomy and Astrophysics.  : EDP Sciences.  00046361 . 14320746. ; 596

Tidskriftsartikel (refereegranskat)abstract
 This paper describes the identification, modelling, and removal of previously unexplained systematic effects in the polarization data of the Planck High Frequency Instrument (HFI) on large angular scales, including new mapmaking and calibration procedures, new and more complete endtoend simulations, and a set of robust internal consistency checks on the resulting maps. These maps, at 100, 143, 217, and 353 GHz, are early versions of those that will be released in final form later in 2016. The improvements allow us to determine the cosmic reionization optical depth tau using, for the first time, the lowmultipole EE data from HFI, reducing significantly the central value and uncertainty, and hence the upper limit. Two different likelihood procedures are used to constrain tau from two estimators of the CMB E and Bmode angular power spectra at 100 and 143 GHz, after debiasing the spectra from a small remaining systematic contamination. These all give fully consistent results. A further consistency test is performed using crosscorrelations derived from the Low Frequency Instrument maps of the Planck 2015 data release and the new HFI data. For this purpose, endtoend analyses of systematic effects from the two instruments are used to demonstrate the near independence of their dominant systematic error residuals. The tightest result comes from the HFIbased tau posterior distribution using the maximum likelihood power spectrum estimator from EE data only, giving a value 0.055 +/ 0.009. In a companion paper these results are discussed in the context of the bestfit Planck Lambda CDM cosmological model and recent models of reionization.


7. 
 Delabrouille, J., et al.
(författare)

Exploring cosmic origins with CORE : Survey requirements and mission design
 2018

Ingår i: Journal of Cosmology and Astroparticle Physics.  : IOP Publishing.  14757516. ; :4

Tidskriftsartikel (refereegranskat)abstract
 Future observations of cosmic microwave background (CMB) polarisation have the potential to answer some of the most fundamental questions of modern physics and cosmology, including: what physical process gave birth to the Universe we see today? What are the dark matter and dark energy that seem to constitute 95% of the energy density of the Universe? Do we need extensions to the standard model of particle physics and fundamental interactions? Is the ACDM cosmological scenario correct, or are we missing an essential piece of the puzzle? In this paper, we list the requirements for a future CMB polarisation survey addressing these scientific objectives, and discuss the design drivers of the CORE space mission proposed to ESA in answer to the M5 call for a mediumsized mission. The rationale and options, and the methodologies used to assess the mission's performance, are of interest to other future CMB mission design studies. CORE has 19 frequency channels, distributed over a broad frequency range, spanning the 60600 GHz interval, to control astrophysical foreground emission. The angular resolution ranges from 2' to 18', and the aggregate CMB sensitivity is about 2 mu K.arcmin. The observations are made with a single integrated focalplane instrument, consisting of an array of 2100 cryogenicallycooled, linearlypolarised detectors at the focus of a 1.2m aperture crossDragone telescope. The mission is designed to minimise all sources of systematic effects, which must be controlled so that no more than 10(4) of the intensity leaks into polarisation maps, and no more than about 1% of Etype polarisation leaks into Btype modes. CORE observes the sky from a large Lissajous orbit around the SunEarth L2 point on an orbit that offers stable observing conditions and avoids contamination from sidelobe pickup of stray radiation originating from the Sun, Earth, and Moon. The entire sky is observed repeatedly during four years of continuous scanning, with a combination of three rotations of the spacecraft over different timescales. With about 50% of the sky covered every few days, this scan strategy provides the mitigation of systematic effects and the internal redundancy that are needed to convincingly extract the primordial Bmode signal on large angular scales, and check with adequate sensitivity the consistency of the observations in several independent data subsets. CORE is designed as a nearultimate CMB polarisation mission which, for optimal complementarity with groundbased observations, will perform the observations that are known to be essential to CMB polarisation science and cannot be obtained by any other means than a dedicated space mission. It will provide wellcharacterised, highlyredundant multifrequency observations of polarisation at all the scales where foreground emission and cosmic variance dominate the final uncertainty for obtaining precision CMB science, as well as 2' angular resolution maps of highfrequency foreground emission in the 300600 GHz frequency range, essential for complementarity with future groundbased observations with large telescopes that can observe the CMB with the same beamsize.


8. 
 Adam, R., et al.
(författare)

Planck intermediate results XLVII. Planck constraints on reionization history
 2016

Ingår i: Astronomy and Astrophysics.  : EDP Sciences.  00046361 . 14320746. ; 596

Tidskriftsartikel (refereegranskat)abstract
 We investigate constraints on cosmic reionization extracted from the Planck cosmic microwave background (CMB) data. We combine the Planck CMB anisotropy data in temperature with the lowmultipole polarization data to fit Lambda CDM models with various parameterizations of the reionization history. We obtain a Thomson optical depth tau = 0.058 +/ 0.012 for the commonly adopted instantaneous reionization model. This confirms, with data solely from CMB anisotropies, the low value suggested by combining Planck 2015 results with other data sets, and also reduces the uncertainties. We reconstruct the history of the ionization fraction using either a symmetric or an asymmetric model for the transition between the neutral and ionized phases. To determine better constraints on the duration of the reionization process, we also make use of measurements of the amplitude of the kinetic SunyaevZeldovich (kSZ) effect using additional information from the highresolution Atacama Cosmology Telescope and South Pole Telescope experiments. The average redshift at which reionization occurs is found to lie between z = 7.8 and 8.8, depending on the model of reionization adopted. Using kSZ constraints and a redshiftsymmetric reionization model, we find an upper limit to the width of the reionization period of Delta z < 2.8. In all cases, we find that the Universe is ionized at less than the 10% level at redshifts above z similar or equal to 10. This suggests that an early onset of reionization is strongly disfavoured by the Planck data. We show that this result also reduces the tension between CMBbased analyses and constraints from other astrophysical sources.


9. 
 Aghanim, N., et al.
(författare)

Planck intermediate results LIII. Detection of velocity dispersion from the kinetic SunyaevZeldovich effect
 2018

Ingår i: Astronomy and Astrophysics.  : EDP Sciences.  00046361 . 14320746. ; 617

Tidskriftsartikel (refereegranskat)abstract
 Using the Planck fullmission data, we present a detection of the temperature (and therefore velocity) dispersion due to the kinetic SunyaevZeldovich (kSZ) effect from clusters of galaxies. To suppress the primary CMB and instrumental noise we derive a matched filter and then convolve it with the Planck foregroundcleaned 2D ILC maps. By using the Meta Catalogue of Xray detected Clusters of galaxies (MCXC), we determine the normalized rms dispersion of the temperature fluctuations at the positions of clusters, finding that this shows excess variance compared with the noise expectation. We then build an unbiased statistical estimator of the signal, determining that the normalized mean temperature dispersion of 1526 clusters is <(Delta T/T)(2))> = (1.64 +/ 0.48) x 10(11). However, comparison with analytic calculations and simulations suggest that around 0.7 sigma of this result is due to cluster lensing rather than the kSZ effect. By correcting this, the temperature dispersion is measured to be <(Delta T/T)(2))> = (1.35 +/ 0.48) x 10(11), which gives a detection at the 2.8 sigma level. We further convert uniformweight temperature dispersion into a measurement of the lineofsight velocity dispersion, by using estimates of the optical depth of each cluster (which introduces additional uncertainty into the estimate). We find that the velocity dispersion is (v(2)) = (123 000 +/ 71 000) (km s(1))(2), which is consistent with findings from other largescale structure studies, and provides direct evidence of statistical homogeneity on scales of 600 h(1) Mpc. Our study shows the promise of using crosscorrelations of the kSZ effect with largescale structure in order to constrain the growth of structure.


10. 
 Ade, Peter, et al.
(författare)

The Simons Observatory : science goals and forecasts
 2019

Ingår i: Journal of Cosmology and Astroparticle Physics.  : IOP Publishing.  14757516. ; :2

Tidskriftsartikel (refereegranskat)abstract
 The Simons Observatory (SO) is a new cosmic microwave background experiment being built on Cerro Toco in Chile, due to begin observations in the early 2020s. We describe the scientific goals of the experiment, motivate the design, and forecast its performance. SO will measure the temperature and polarization anisotropy of the cosmic microwave background in six frequency bands centered at: 27, 39, 93, 145, 225 and 280 GHz. The initial con figuration of SO will have three smallaperture 0.5m telescopes and one largeaperture 6m telescope, with a total of 60,000 cryogenic bolometers. Our key science goals are to characterize the primordial perturbations, measure the number of relativistic species and the mass of neutrinos, test for deviations from a cosmological constant, improve our understanding of galaxy evolution, and constrain the duration of reionization. The small aperture telescopes will target the largest angular scales observable from Chile, mapping approximate to 10% of the sky to a white noise level of 2 mu Karcmin in combined 93 and 145 GHz bands, to measure the primordial tensortoscalar ratio, r, at a target level of sigma(r) = 0.003. The large aperture telescope will map approximate to 40% of the sky at arcminute angular resolution to an expected white noise level of 6 mu Karcmin in combined 93 and 145 GHz bands, overlapping with the majority of the Large Synoptic Survey Telescope sky region and partially with the Dark Energy Spectroscopic Instrument. With up to an order of magnitude lower polarization noise than maps from the Planck satellite, the highresolution sky maps will constrain cosmological parameters derived from the damping tail, gravitational lensing of the microwave background, the primordial bispectrum, and the thermal and kinematic SunyaevZel'dovich effects, and will aid in delensing the largeangle polarization signal to measure the tensortoscalar ratio. The survey will also provide a legacy catalog of 16,000 galaxy clusters and more than 20,000 extragalactic sources.

